Root canal instrument

Abstract

The present invention relates to a root canal instrument for manual use, the instrument comprising a grip member 1 which has attached thereto an elongated tapering shaft 2 which is provided with at least one cutting edge coiled in spiral form around the longitudinal axis 8 of the shaft 2 , characterized in that the shaft 2 has a cross-sectional shape which is provided at two opposite sides with one cutting edge 3, 4 each and whose side surfaces 5, 6 connecting the cutting edges 3, 4 are each made convex.

What is claimed is:  
     
         1 . A root canal instrument for manual use, comprising a grip member ( 1 ) which has attached thereto an elongated tapering shaft ( 2 ) which is provided with at least one cutting edge coiled in spiral form around the longitudinal axis ( 8 ) of said shaft ( 2 ), characterized in that said shaft ( 2 ) has a cross-sectional shape which is provided at two opposite sides with one cutting edge ( 3 ,  4 ) each and whose side surfaces ( 5 ,  6 ) connecting said cutting edges ( 3 ,  4 ) are each made convex.  
     
     
         2 . The root canal instrument according to  claim 1 , characterized in that the tangent angle at said cutting edge ( 3 ,  4 ) is made to range between 70° and 110°.  
     
     
         3 . The root canal instrument according to  claim 1 , characterized in that said cutting edge ( 3 ,  4 ) is made symmetrical relative to a straight line ( 7 ) or plane connecting said two cutting edges ( 3 ,  4 ).  
     
     
         4 . The root canal instrument according to  claim 1 , characterized in that the two cutting edges ( 3 ,  4 ) are made identical.  
     
     
         5 . The root canal instrument according to  claim 1 , characterized in that said two side surfaces ( 5 ,  6 ) are curved in the form of an arc.  
     
     
         6 . The root canal instrument according to  claim 5 , characterized in that said two side surfaces ( 5 ,  6 ) are curved in the form of a circular arc.  
     
     
         7 . The root canal instrument according to  claim 1 , characterized in that said two side surfaces ( 5 ,  6 ) are made symmetrical relative to said straight line ( 7 ) or plane connecting said cutting edges ( 5 ,  6 ).  
     
     
         8 . The root canal instrument according to  claim 1 , characterized in that the front portion ( 9 ) of said shaft ( 2 ) is configured to be non-cutting.  
     
     
         9 . The root canal instrument according to  claim 2 , characterized in that said cutting edge ( 3 ,  4 ) is made symmetrical relative to a straight line ( 7 ) or plane connecting said two cutting edges ( 3 ,  4 ).  
     
     
         10 . The root canal instrument according to  claim 2 , characterized in that the two cutting edges ( 3 ,  4 ) are made identical.  
     
     
         11 . The root canal instrument according to  claim 3 , characterized in that the two cutting edges ( 3 ,  4 ) are made identical.  
     
     
         12 . The root canal instrument according to  claim 2 , characterized in that said two side surfaces ( 5 ,  6 ) are curved in the form of an arc.  
     
     
         13 . The root canal instrument according to  claim 3 , characterized in that said two side surfaces ( 5 ,  6 ) are curved in the form of an arc.  
     
     
         14 . The root canal instrument according to  claim 4 , characterized in that said two side surfaces ( 5 ,  6 ) are curved in the form of an arc.  
     
     
         15 . The root canal instrument according to  claim 2 , characterized in that said two side surfaces ( 5 ,  6 ) are made symmetrical relative to said straight line ( 7 ) or plane connecting said cutting edges ( 5 ,  6 ).  
     
     
         16 . The root canal instrument according to  claim 3 , characterized in that said two side surfaces ( 5 ,  6 ) are made symmetrical relative to said straight line ( 7 ) or plane connecting said cutting edges ( 5 ,  6 ).  
     
     
         17 . The root canal instrument according to  claim 4 , characterized in that said two side surfaces ( 5 ,  6 ) are made symmetrical relative to said straight line ( 7 ) or plane connecting said cutting edges ( 5 ,  6 ).  
     
     
         18 . The root canal instrument according to  claim 5 , characterized in that said two side surfaces ( 5 ,  6 ) are made symmetrical relative to said straight line ( 7 ) or plane connecting said cutting edges ( 5 ,  6 ).  
     
     
         19 . The root canal instrument according to  claim 6 , characterized in that said two side surfaces ( 5 ,  6 ) are made symmetrical relative to said straight line ( 7 ) or plane connecting said cutting edges ( 5 ,  6 ).  
     
     
         20 . The root canal instrument according to  claim 2 , characterized in that the front portion ( 9 ) of said shaft ( 2 ) is configured to be non-cutting.